I am sure all of us have seen Collateral which is a great and entertaining movie. Of course Tom Cruise was a fantastic shot in the movie.

I have a few questions about some of the things we see in the movie though.

#1) During the briefcase robbery scene, Vincent slaps the gun arm of the would-be robber down then draws and fires on both assailants.

I have seen someone on youtube doing a very similar drill where the shooter starts with their hand touching the target, the start buzzer goes off and the shooter backs up (sometimes slapping the target first) and then takes their shots. Is there a name for this drill?
You can see an example of this drill at about 0:41 in this youtube clip:http://www.youtube.com/watch?v=JbC5mEc6ipE

#2) Repeatedly, Vincent fires from the hip after a quick draw with a single handed grip, with his other hand above the gun kind of like you'd see in an old western movie, slapping the hammer back on his revolver. In Collateral Vincent is using an HK45 so no need for hammer slapping - is there a reason he does this and can someone explain it to me?